This invention relates to an effective technique for packaging of a high density module used, for example, in an electronic computer system.
To improve packaging density of electronic devices such as semiconductor devices, it is a recent trend to use a module of an SIP (Single In-Line Package) structure. The SIP structure includes a substrate for mounting electronic devices, formed by a multi-layered substrate fabrication technique with, semiconductor parts mounted to both surfaces of this substrate and external electrodes disposed along one of the edges of the substrate.
The multi-layered substrate fabrication technique is disclosed, for example, in "VLSI Device Handbook", published by K.K. Science Forum, Nov. 28, 1983, pp. 239-250.
In semiconductor devices of the SIP structure wherein a plurality of face-package type semiconductor parts are mounted to both surfaces of a substrate such as a memory module consisting of DRAM, for example, it has been customary to mount them to a mother board or a socket in a vertical direction.